[Problems of postthymectomy-syndromes, e.g. myasthenia gravis (author's transl)]

6 years after resection and postirradiation of an "asymptomatic" thymoma, myasthenia gravis developed in a 46 year old man which improved within 6 months following initiation of immunosuppressive therapy with azathioprine. In a 28 year old man with incomplete operative removal of a metastasizing malignant thymoma, a myasthenia gravis appeared 8 weeks after surgery, i.e. before irradiation of the tumor relics. Myasthenia improved upon irradiation of the tumor relics and was no longer demonstrable one year after onset of its clinical signs. During the whole period of manifestation of the myasthenia, antibodies to skeletal muscle were deomonstrated in the first case, while, in the second case, in which antinuclear factors were present in the serum throughout the course of the myasthenia, muscular antibodies were detected only prefinally, i.e. in a stage without clinical symptoms of myasthenia. A review of the literature indicates that myasthenia gravis is a particularly frequent event in postthymectomy-syndromes (e.g. polymyositis, thyreoiditis, lupus erythematosus, hematological and dermatological syndromes). In postthymectomy-myasthenia, latency of manifestation, clinical distribution and its course may be rather variable. The problems of diagnosis, immunology and therapy of postthymectomy-myasthenia are discussed and general conclusions concerning postthymectomy-syndromes are drawn.